This application claims the benefit under 35 U.S.C. 119(a) of Korean Patent Application Nos. 10-2004-0055887, filed on Jul. 19, 2004, 10-2004-0055888, filed on Jul. 19, 2004 and 10-2004-0055889, filed on Jul. 19, 2004, respectively, in the Korean Intellectual Property Office, the entire disclosures of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a printing method and apparatus using a thermal print head (TPH). More particularly, the present invention relates to a printing method and apparatus using a shuttle TPH, which can print an image by moving the TPH in a transverse direction.
2. Description of the Related Art
A thermal transfer printing apparatus forms an image by transferring ink to a medium by heating an ink ribbon attached to the medium using a thermal print head (TPH) or forms an image by heating a medium on which an ink layer of a predetermined color is formed in response to heat emitted by a TPH.
FIG. 1 is a schematic top view of a conventional thermal transfer printing apparatus. Referring to FIG. 1, the printing apparatus includes a thermal print head (TPH) 100, a TPH nozzle 120, a platen roller 140, and a feeder 155. The feeder 155 includes a motor 160, a driving roller 170, a following roller 180, and a media sensor 190.
The TPH 100 heats a medium fed by the feeder 155. The TPH nozzle 120 supplies ink required for printing onto the platen roller 140. The platen roller 140 is placed in front of the TPH 100 while a medium is inserted between the platen roller 140 and the TPH 100, supports the medium for ink to adhere thereto, and rotates when the medium is fed.
The motor 160 is a power source for supplying a printing medium to the TPH 100, and the driving roller 170 feeds the medium by being engaged with the motor 140 and rotating. The following roller 180 feeds the medium by being engaged with the driving roller 170 and rotating while the medium is inserted between the driving roller 170 and the following roller 180. The media sensor 190 detects a position of the printing medium.
FIG. 2 is an image printed using the conventional thermal transfer printing apparatus of FIG. 1. The image shown in FIG. 2 is printed using a TPH having heating elements corresponding to 300 dots per inch (dpi), and a printing resolution is also 300 dpi, equal to the number of heating elements of the TPH.
As described above, when the conventional thermal transfer printing apparatus is used, since a printing region having a transverse length longer than a length of a TPH cannot be printed, the size of the TPH must be increased to print on a large sized medium. Therefore, manufacturing costs power consumption and heat dissipation increase.
Also, when the conventional thermal transfer printing apparatus is used, printing is performed with only a predetermined resolution according to the number of heating elements of the TPH. Therefore, since the number of heating elements of the TPH must be increased to perform high quality printing by increasing the printing resolution, the manufacturing cost increases, and the temporary consumption of power and heat dissipation of the printing apparatus increases.
Also, when heat is applied on a medium using two TPHs in order to perform color printing on the medium, a color to be printed may not be printed due to a distance deviation between the two TPHs. Therefore, an alignment compensation for matching positions of the two TPHs is required.
Therefore, there is a need for a TPH that can print on a large sized medium without greatly increasing power consumption or heat dissipation.